Sorry about the weird url format, the forum won't let me post url's because I don't have enough posts apparently, but it is a pretty useful little free utility for generating all kind of checksums.

[EDIT: Carpetsmoker: Made proper link -- After 10 posts you'll be able to post links, this is an anti-spam measure, I'm sorry for the inconvenience.
Welcome to the forums and thanks for your contribution]

Last edited by Carpetsmoker; 26th June 2009 at 06:53 AM.
Reason: Make link

I just wish someone had shared an example command line to do an actual checksum confirmation. I spent quite a few minutes working this one out. I think the man page synopsis may be wrong or inaccurate, and it doesn't mention exit status quietly used to confirm check. Also, big files take a small while to check so you can't do too many tests quickly and not sure if it's actually hung or waiting for input. I tried pipeing file into the command as well at one point.